Technical Field
The present disclosure relates to surgical instruments and, more particularly, to bifurcated shafts for use with surgical instruments.
Description of Related Art
Electrosurgical instruments (e.g., surgical forceps) are well known in the medical field, and typically include a handle, a shaft, and an end effector assembly that is operatively coupled to a distal portion of the shaft to manipulate tissue (e.g., grasp and seal tissue). Electrosurgical instruments utilize both mechanical clamping action and electrical energy to effect hemostasis by heating the tissue and blood vessels to coagulate, cauterize, seal, cut, desiccate, and/or fulgurate tissue.
As an alternative to open electrosurgical instruments for use with open surgical procedures, many modern surgeons use endoscopes and endoscopic electrosurgical instruments (e.g., endoscopic forceps) for remotely accessing organs through smaller, puncture-like incisions. As a direct result thereof, patients tend to benefit from less scarring, fewer infections, shorter hospital stays, less pain, less restriction of activity, and reduced healing time. Typically, the endoscopic electrosurgical instrument is inserted into the patient through one or more various types of cannulas or access ports (typically having an opening that ranges from about five millimeters to about twelve millimeters) that has been made with a trocar.
Conventional electrosurgical instruments include a pair of jaw members that have a common pivot point (e.g., a pivot pin) disposed towards proximal ends thereof that facilitates manipulation of the jaw members between open and closed positions. In addition, the pivot point facilitates application of pressure by the jaw members to tissue grasped therebetween by preventing the opposed jaw surfaces from moving away from each other at the proximal ends of the jaw members. In this manner, when tissue is grasped between the opposing jaw members, a V-shaped configuration is defined therebetween since the distal ends of the jaw members are further away from each other than the proximal ends of the jaw members. When smaller-diametered tissue is grasped between the jaw members, the V-shaped configuration does not create any substantial problems, since the opposing jaw members are substantially parallel and relatively close to each other. However, when larger-diametered tissue is grasped between the jaw members, the opposing jaw surfaces are not substantially parallel to each other and further away from each other, thus inhibiting complete closure of the jaw members. More particularly, when larger-diametered tissue is grasped between the jaw members, the current density applied to tissue grasped therebetween during surgical treatment (e.g., fusion or ablation) tends to be substantially higher at the proximal end of the jaw members than towards the distal portion thereof, which creates uneven tissue fusion, or uneven ablation.